I don't understand why a police cruiser can sit in a public space (or even a private one) and write down licence plates and descriptions of passers-by with pen and paper, or record everything around them with dashcams and bodycams for later use, but when it comes to cameras on a pole this would require a warrant.

Going back through police officers' notes or cruiser dash cam videos and tracking a car's movements by its plate is not an illegal search, is it? Just cumbersome, expensive and likely ineffective. Well, now it's not. A difference in degree (of usefulness and speed), not in kind.

You've already gotten a lot of replies about difference in degree, but there's also two differences in kind: one with visibility, and one with capability.

A police cruiser sitting at an intersection is visible. People notice it and its presence changes their behavior. They may choose to avoid certain routes through a city where surveillance cruisers hang out. Flock, and similar surveillance systems, are far less noticeable. Many, many people had no idea they existed a year ago when there were already 80,000 devices installed. Flock has been hot in the news cycle lately in part because tons of people are still just beginning to learn they exist. Whereas a police cruiser on a corner is overt surveillance, Flock is a "creepier" incarnation.

There's also capability. In principle, an officer parked on a corner is capable of responding to a variety emergencies. Some people might feel that the presence of the officer there was a net good for public safety. Heart attack in the neighborhood? Your local surveillance officer can start CPR. Older person with late-stage dementia has just walked away from home? Your local surveillance officer could clear that neighborhood.

But these surveillance systems have only one capability: surveillance. They can't render aid. They can't even prevent a crime; they can, at best, discourage it, or maybe aid in the apprehension of someone who committed a crime -- and didn't take adequate measures to avoid detection.

> I don't understand why a police cruiser can sit in a public space (or even a private one) and write down licence plates and descriptions of passers-by with pen and paper, or record everything around them with dashcams and bodycams for later use, but when it comes to cameras on a pole this would require a warrant.

Scale actually matters. Things that are generally OK at a small scale become problematic at larger scales. A single police cruiser writing down license plates isn't able to track you in the same way a huge surveillance network is, and the opportunities for abuse are much lower.

Former law enforcement officer here. I can say that when we conducted surveillance, we weren't allowed to use equipment that wasn't common for normal people to use. So for example, I couldn't use some sort of long-distance microphone to overhear a conversation between two people in public because a normal person wouldn't have that same type of technology. I think this applies in this context to say that a cop just scanning and logging every single plate that traverses a certain area is outside the bounds of what we'd consider lawful for normal surveillance. Alternatively, if a normal person would just sit down and write down every single car description and plate that passed by their house or any other public area, a cop doing the same thing would be reasonable. The scale of modern data collection for police is whats dangerous to individual privacy rights.

But you can generally FOIL records of this. Want body cam footage of what the officer was doing, you can generally get that. Want the video footage from their dash cam while sitting there, you can generally get that. However municipalities treat the data from these license plate cameras like a state secret. That disparity is largely what’s at issue here.

A difference of a sufficient degree becomes a difference in kind, because whatever the internal justifications, the external implications of the system for society change drastically.

If your police force installed officers in parked cruisers at every intersection to record license plate numbers and then digitized that information so you can build up a dossier of times and locations for a given individual without probable cause that would be both illegal and a huge waste of resources. ALPR just do it at scale so it's cheaper; still illegal without cause.

> A difference in degree

But a pretty huge difference. It's the difference between a few individuals throwing waste into a river vs a corporation systemically polluting it. Surely one is more of a problem than the other?

Once you remove constraints imposed by needing actual labor you make it a difference in kind since you are allowing for tracking of anyone versus having limited information on a limited area.

If the police stationed officers constantly at major intersections doing that, the outcry would be no less than having cameras do it.

Also, if it's the police, at least they're part of the community and people can monitor and have an effect on what they do. When it's a private company, none of that is true.

Because of the scale: ALPR’s track where everyone is and was all the time. This allows entire categories of intimate information to be learned, that clearly threaten the civil liberties that the 4th amendment was written to protect.

For example, an officer sitting on a city street is very unlikely to learn where his wife goes every day, an ALPR search will answer that question.

An officer walking along the street making note of what he sees is very unlikely to observe and make note of the precise daily movements of someone in August three years ago, an ALPR search will answer that question.

The degree/kind distinction you’re aiming at is meaningless, it’s like trying to argue that shooting someone with a firearm is the same as shooting someone with a paintball gun in principle, sure but maybe one of them is orders of magnitudes morw powerful and impactful, and so deserves a different degree of consideration in how and when it is applied?

They can. That’s fine, let them do that.

The difference in scale is so great that it becomes the meaningful, defining factor.

Police already don’t need warrants to gather video footage from homes and businesses. It certainly isn’t ineffective or else they wouldn’t do it, but everybody knows how effective video footage is. The difference for most does seem to be that it doesn’t cost man hours. We have had cities in the USA with 10k+ cameras in public spaces for years now without much fanfare.

A difference in degree is a difference in kind. Computer scientists struggle with a lot of legal concepts because they love to reduce situations in attempt to distill some particular facet and argue from analogy. A lot of poor legal analysis regarding things like fraud go similarly: “well in principle isn’t this the same as if I just . . .”

If there were literally hundreds of thousands of government agents on every corner writing down every person/car that walked by, it is quite probable this would be illegal even though you have no expectation of privacy in public. See Carpenter V United States and some of the concurring opinions in United States v. Jones.

Because if you wanted to hire the number of police to sit and monitor a public space equal to the number of flock ALPRs you would probably quickly become larger than your average city's entire budget

Would you feel similarly if microphones were installed everywhere to record all public conversations for analysis via algorithms? Is that the same as police officers listening to conversation in a public space and taking notes?

Simply replace every pole with an officer in their cruiser then and we’ll all be happy.

I believe you’re trying to articulate the act of witnessing from the act of investigating, and where the boundary between the two is. To me it seems like the boundary should be “does the general public have access to this information?”. If so, it’s allowable. If not, then a justification should be required for starting an investigation.

As someone who strongly opposes flock cameras...

This is a huge problem that people will try to sweep under the rug or hand wave away with wording like "It's the scale the matters".

Ideally, laws need to be written like programs are, where fundamental rules of the system are derived and programmatically put into action. So words like "scale" mean nothing. "I need the variable to go negative when the scale is large". Most programmers here will immediately snag on "scale" not being a hard value.

So what we actually need is a redefining of the fundamental rules, and well, that is very challenging to do such that it's still legal to walk around an record everything in public, but not legal to passively record everything in public all the time. How do we solidly and unambiguously differentiate a cops dashcam, from a police camera on a portable base station, from a flock camera on a corner to a private business with a security came to a firestation with a security camera.

Legally it's a very challenging problem to create a "programmatic differentiation" from the kind of camera use we want, and the kind we don't want.

right now, neither needs a warrant. if searching LPR camera history starts to require a warrant, it probably wouldn't take much to argue that sending officers out to manually do the same thing should require one too.

EDIT: i have no doubt that Flock and other ALPRs got so widespread because four ALPRs watching each direction at an intersection is basically invisible in comparison to four cop cars at every intersection.

if plate readers were as visible as cop cars (including agency branding) people would have probably gotten bent out of shape a long time ago.

The degree is the problem. I’d have similar complaints if each Flock camera were replaced with an around-the-clock staff of police officers recording every license plate.

Have you met cops? They are not able to sit still or write things down. You expect too much of them.

> I don't understand why a police cruiser can sit in a public space (or even a private one) and write down licence plates and descriptions of passers-by with pen and paper, or record everything around them with dashcams and bodycams for later use, but when it comes to cameras on a pole this would require a warrant.

Similar issue: cell phone interception via Stinger cell base stations by law enforcement. A U.S. judge in Ohio ruled that using the device to sweep up data from thousands of unsuspecting individuals to track one suspect gave the government unconstitutional, "unbridled discretion" to monitor private citizens.

Another similar issue: A judge in Mississippi ruled "tower-dump warrants", where law enforcement requests info from cell companies on users/phone numbers in a geographic area in a certain time frame are illegal and too broad. The judge declared them an arbitrary government intrusion that violates the Fourth Amendment's particularity requirement

A third similar issue: In U.S. v. Chatrie, the U.S. Supreme Court ruled 6-3 that reverse-location "geofence warrants" constitute a Fourth Amendment search. The ruling establishes that users maintain a reasonable expectation of privacy over their location data, meaning law enforcement can no longer execute warrantless, sweeping digital dragnets through third-party data.

These are 3 examples of large scale police surveillance that have been ruled illegal because they are broad surveillance and give police too much power without a specific legal justification. This seems very similar and I expect the court cases on ALPR cameras to end up in the same place, but it may take a decade or so.

Aggregation. Correlation.

License plates are public property.

look into "dragnet"'s as that's the term (afaik) and the issue at hand.

Because the physical impossibility of a department doing that 24/7 every square inch of a city creates an expectation of privacy.

You are comparing individual human observation with an automated surveillance network. Their capabilities are vastly different. It's like comparing a taser with an M1 Abrams tank.

When it comes to surveillance, it is not enough to say "difference in degree, not in kind". The difference is the degree. Memorising someone's face is not surveillance, building a database of faces is. Seeing someone you recognize go into a store is not surveillance, writing down everywhere they go during the day is.

Because the ability to scale up a bunch of officers sitting around writing down literally everything they see is limited in comparison. It can only be so invasive and “always-on” everywhere. Throwing up a few dozen flock cameras costs a fraction of that and scales incredibly quickly.